This invention relates to an improved nebulizer mouthpiece and accessories.
Our earlier U.S. Pat. No. 5,584,285, discloses a nebulizer with a mouthpiece having a flap valve 124 shown in FIG. 3 of the patent which is reproduced here as FIG. A. When the patient exhales into the mouthpiece 126 the air pressure causes the flap 124 to open and let the exhaust air out of the mouthpiece.
This early design, while operational and commercially effective, is not optimal. Since the flap valve 124 is in the path of the incoming inspiration mist, there is the possibility that the mist under sufficient pressure can cause the flap to slightly open such that some of the mist will leave the mouthpiece in the form of rainout before it reaches the patient. When the patient exhales, there is no structure to direct the exhaust flow against the valve or increase back pressure to assist the valve opening. The valve only opens when the exhaust gas back pressure reaches a certain level. The flap valve is made of a stiff yet flexible material and thus it will inherently have some resistance to opening at very low pressures. If any rainout accumulates on the external surface of the flap valve, it is also difficult for the liquid material to flow back into the mouthpiece. The inner peripheral surface of the flap may stick to the overlapping external surface of the mouthpiece when the inner surface of the flap is wet.
It is an object of this invention to provide an improved mouthpiece exhalation valve for a nebulizer or breathing circuit containing a nebulizer where the design of the internal passageway contains an offset which causes the inspiration mist flow to bypass the exhaust valve without impingement together with a filter arrangement associated with the exhaust valve and a positive expiratory pressure valve and/or a positive expiratory pressure (PEP) valve.
According to the invention there is provided a mouthpiece device for inspiration of a mist from a nebulizer comprising: an inlet connector adapted to engage the outlet port of a nebulizer; a hollow mouthpiece element for insertion into a patient""s mouth, a conduit forming a fluid connection between the inlet connector and the hollow mouthpiece element; an exhaust valve for removing exhalation gases which are exhaled into the mouthpiece element to outside the device, said exhaust valve being positioned on the conduit between the inlet connector and the mouthpiece element; and a filter housing incorporating a filter to filter exhaled gases passing from the exhaust valve.
Also according to the invention there is provided a mouthpiece device for inspiration of a mist from a nebulizer comprising: an inlet connector adapted to engage the outlet port of a nebulizer; a hollow mouthpiece element for insertion into a patient""s mouth, a conduit forming a fluid connection between the inlet connector and the hollow mouthpiece element; an exhaust valve for removing exhalation gases which are exhaled into the mouthpiece element to outside the device, said exhaust valve being positioned on the conduit between the inlet connector and the mouthpiece element; and a positive expiratory pressure valve is disposed to produce a back pressure in the gases exhaled through the exhaust valve.
Also according to the invention, there is provided a mouthpiece device for inspiration of a mist from a nebulizer comprising: an inlet connector adapted to engage the outlet port of a nebulizer; a hollow mouthpiece element for insertion into a patient""s mouth, a conduit forming a fluid connection between the inlet connector and the hollow mouthpiece element; an exhaust outlet for removing exhalation gases which are exhaled into the mouthpiece element to outside the device, said exhaust outlet being positioned on the conduit between the inlet connector and the mouthpiece element; and a positive expiratory pressure valve is disposed to produce a back pressure in the gases exhaled through the exhaust outlet.
Also according to the invention there is provided a method for breathing an inspiration of a mist from a nebulizer comprising: using a mouthpiece element having an inlet connector adapted to engage the outlet port of a nebulizer; a hollow mouthpiece element for insertion into a patient""s mouth; a conduit forming a fluid connection between the inlet connector and the hollow mouthpiece element; an exhaust valve positioned on the conduit between the inlet connector and the mouthpiece element for removing exhalation gases which are exhaled into the mouthpiece element to outside the device; and a filter housing incorporating a filter to filter exhaled gases passing from the exhaust valve.